On a somewhat related note, what actually goes on these things? I mean, how do you thank someone for asking you interview questions? Likewise with the residents at lunches...
A good thank you note has three components:
1. Thank the interviewer for his/her time. January is busy enough without having to carve out time to read someone's application materials and then actually spend 30-60 minutes with them.
2. Highlight one key thing about you as an applicant. Either refer to it being discussed during the interview (in context) or, if by chance you forgot to mention something important, you can also mention in in the thank you note (hopefully you haven't, though).
3. Express your hope to be selected for the program/invited for the next round of interviews (whatever applies).
Plus, I would use the greeting of "Dear So-and-So" instead of something less formal (even if you choose to write an e-mail). Whether to use first name or Dr. So-and-So - depends on the tone of the interview and who the interviewer is.
As far as complimentary close, Sincerely yours is the safest option. If the interview was very warm in tone, I would use Cordially yours on occasion.
And don't overthink it. I don't know anyone who would pore over thank you notes or compare the notes from different candidates. Unless it is spectacularly bad, it will just get looked at and filed with the rest of the application or put somewhere on the interviewer's desk to be buried under piles of work-related papers in a few days.
🙂
PS The best deal is the boxes of 10 or 20 blank thank you notes. Very functional. And, unlike Christmas cards going to elderly family members, you can send the same ones to all interviewers, they won't get offended.
😀